I am working on moving a site from Rackspace Cloud Sites onto a server running IIS and need to get the SSL certificate imported into IIS. All I have at the moment for the SSL certificate is what Rackspace gives me.
The text of the certificate
-----BEGIN CERTIFICATE-----
etc.
-----END CERTIFICATE-----

How to decrypt an encrypted private key:

If your PFX file was created correctly, but you receive an error like "Connection Interrupted" when browsing SSL on your website after installing the certificate, try rebooting the server. It has worked for me in the past. If it doesn't, your private key probably does not match your certificate.

OpenSSL will do this for you, given the cert and keys like this you can combine them into a PKCS#12 format which should work in most cases where .PFX is specified. The documentation for OpenSSL has detailed examples.